Various compositions for the correction of typewritten or other printed material have been known for some time. For example, U.S. Pat. No. 3,276,870 discloses a correction fluid comprising a pigment and a resin binder in a solvent for the binder such as toluene or methyl ethyl ketone. This sort of correction fluid works well when applied to certain types of printed material such as those created by the use of inks consisting of a dye or pigment in a solvent in which drying is accomplished by rapid penetration of the ink into the paper and evaporation of the solvent, since little difficulty is encountered in providing a solvent for the resin binder in the correction fluid which is a non-solvent for the dye or pigment of the ink.
The advent of inks comprised of a pigment dispersed in an organic resin in which the ink image is deposited on the substrate and heat or solvent fused to a continuous film (as in the case of electrostatic printing) or pressure fused (as in the case of certain typing methods) has created problems with the use of correction fluids containing conventional organic liquids as solvent for the resin binder of the correction fluid. This is the case because the use of these correction fluids to correct documents in which the image is of the organic resin/pigment type ink results in the resin binder of the ink being at least partially dissolved by the correction fluid. This dissolution of the ink resin during application of the correction fluid results in release of the ink pigment, which is usually black, into the correction fluid. The release of this black pigment into the correction fluid, which is usually pigmented white, results in a smeary, gray colored coating which is, of course, undesirable. In order to obtain a white area upon correction of an error, the use of successive applications of the correction fluid is necessary.
Accordingly, it would be desirable, and it is an object of the present invention to provide a novel correction fluid for printed and/or typed matter.
An additional object is to provide such a correction fluid which is suitable for use in correcting printed matter which contains an image of an organic resin having a pigment dispersed in it which is fused onto a paper backing.
A further object is to provide such a correction fluid which can be used to cover an image of the resin/pigment ink to provide a clean white surface in a single application.